


A Common Mistake

by scrub456



Series: Towel Day 2017 [4]
Category: Sherlock (TV), Sherlock Holmes & Related Fandoms
Genre: BAMF John, BAMF Mrs. Hudson, Douglas Adams, Gen, Heist, Humor, Light Whump, Mrs Hudson's car, OOC, Towel Day 2017, but with intent, idiots being idiots, this is kind of ridiculous
Language: English
Status: Completed
Published: 2017-05-27
Updated: 2017-05-27
Packaged: 2018-11-05 15:16:50
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,222
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11016069
Author URL: https://archiveofourown.org/users/scrub456/pseuds/scrub456
Summary: "A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.” - Douglas Adams





	A Common Mistake

**Author's Note:**

  * For [notjustmom](https://archiveofourown.org/users/notjustmom/gifts).



> To my heart. You make every day easier, but most especially these last several. I love you so. ♡
> 
> ******
> 
> I have no idea at what point in time within canon this story happens, but the boys see Mrs. Hudson's car for the first time, and John meets Mummy Holmes. And, in case it isn't obvious from the prompt, most of this is OOC, with intent.

“You can be a right arse sometimes.” John winced when he rolled his left shoulder, extended his arm, then flexed his fingers. He glanced at Sherlock just in time to see the smug bastard smirk. He slowed his pace to match John's stride. “Brilliant as always…”

“But?” Sherlock rolled his eyes and sighed his impatience with the conversation. 

“Lastrade did us a favor letting us look at this case. Was all of _that_ ,” John waved his left hand at Sherlock, then flexed his fingers again, “really necessary?”

“All of what? You know my methods, John. They all know my methods!” Pressing his lips tight in disdain, Sherlock pouted at the implication.

“Stop that,” John chuckled. “You know what I mean. You had Donovan in such a fit, the suspect got away from her. He nearly escaped because you had to make a public spectacle of exercising that massive intellect of yours.”

“I knew you could, and would, subdue him. And you did. Good on you. Dim sum?” Sherlock motioned to their regular place just up the block.

John laughed outright. “Thanks, I think.” He rolled his shoulder again and noticed his untied shoelace. “Sure. Let me just…” Dropping to a crouch -- one need always keep one’s head up, the army taught him that -- he was nearly stunned by the rapid succession of events.

“John!” Sherlock shouted as he lunged and landed a solid right hook on a man in a black suit who had moments before been walking innocently towards them. Almost instantly a second man in a suit had tossed Sherlock, rather gruffly, and pinned him against a wall.

A third man, John could only assume he too was wearing a suit, grabbed him by the collar and jerked him up to standing. He managed an elbow to his assailant’s groin on the way up, and he slammed his head back and directly into the other man’s nose. Suit One landed a few surprise blows, one to John’s jaw, and two to his abdomen, causing him to double over. 

“John!” Sherlock struggled against Suit Two, and looked like he'd really given him hell, but had ended up restrained and it appeared he'd been drugged.

“Sherlock! You bastards, what did you do to him?” John charged after the men loading Sherlock into a black sedan.

“Don't make this harder than it has to be, Doctor Watson. Just get in the car.” Bloody faced Suit Three stood between him and Sherlock.

“Like bloody hell,” John growled as he charged. The suit dodged his right handed attempt, and landed a blow of his own. John’s swing with his aching left arm was ineffectual, and he soon found himself flat on his back.

“Boss says leave ‘em. We got Holmes. Primary target obtained. Watson’ll just be a liability.” One of the suits called from the car.

“Don't think I don't know who you are or where you're taking him.” John rasped. A heavy soled kick to his ribs and John curled in on himself.

“Then you know how this works. There will be a car…”

“You can sod off!” John spat. “And you can tell your boss to go to hell.” Another kick to John’s ribs, and Suit Three climbed into the car and they sped away.

“Nothing broken,” John groaned as he pulled himself up from the sidewalk. “But that arsehole certainly didn't pull any of his punches. Damn.” John started the slow trek home, but as an afterthought, turned to the nearest cctv camera and demonstrated a rather vivid catalogue of obscene gestures.

“Oh! Good heavens, John. Are you all right? Where's Sherlock? What have you boys gotten into now?” Mrs. Hudson was on her way out to the shops when John finally dragged himself through the front door. She dropped her bags and began flitting and fussing immediately.

“I'll be fine, Mrs. H.” John smiled warmly at her concern and let her usher him into her flat. “Sherlock's been taken-”

“Oh!” Mrs. Hudson sat the cup she was holding down with a little too much force, and covered her mouth with both hands.

“Not to worry. I know the who, the where, and the why. And I have a plan,” he paused and cocked a conspiratorial eyebrow at her. “I could probably use your help.”

“My help?” She sat down across from him and took his hand. “Anything, John. For our Sherlock.”

“How do you feel about the sciences?”

“Science?” Mrs. Hudson scrunched up her nose. “Well that's really more Sherlock’s area, and yours too dear.” She patted John's hand as if consoling him for medicine making him a man of science to some lesser degree than his flatmate the graduate level chemist.

John rolled his eyes. “Yes, but there's a gala. Tonight. It's a proper event, so your finest dress, maybe a bit of acting, some deception…”

Mrs. Hudson clapped her hands. “Oh, a proper heist, just like in the films! Who's the rest of our crew?”

“Crew?” John chuckled. “Just us. Maybe Molly Hooper.”

“Oh, she's a lamb, isn't she?”

“And I need to call for a car.”

“John, wait!” Mrs. Hudson bustled from the kitchen, and John could hear drawers being searched in the sitting room. “Found them,” she waved a set of keys at John. “We can use mine.”

“Oh, Mrs. H, I'm sure that's-” His eyes went wide as Mrs. Hudson tossed the keys to him and turned her attention to the kettle. “What? Wait…” John examined the fob. “Is this Aston Martin?”

“I keep telling you boys, I'm not your housekeeper. I've got my interests.”

“I, I… I'm sorry. Of course you do. But, for example, what exactly? No, no never mind, I probably don't want to know.” John chanced a glance up at his landlady. “Do I?”

She patted his shoulder and chuckled. “No, dear. No, I should say not.”

“Right.” John shook his head to stave off the unholy imaginations, and sent a quick text to Molly 

“Have some tea, dear. And I'll get some ice for your ribs, I can see you favoring them. Sherlock’s not the only observant one, you know.”

“Thank you, Mrs. H.” John chuckled and allowed Mrs. Hudson to mother him a bit longer. It was against his very nature to allow her to do so, but there were chocolate biscuits -- the ones Sherlock never shared -- and a promise that he could drive the Aston Martin as long as Mrs. Hudson had a say in the final operation.

When John excused himself from Mrs. Hudson's flat so they both could prepare, he reminded her, “The gala starts at 8:00. I'll be down for you at 7:30.”

“Shouldn't we say 1930 instead of 7:30, dear? It sounds so much more… covert.” Mrs. Hudson looked up at John with a glint in her eyes. He couldn't help but laugh.

“Yes, Mrs. H. It does sound very Bond, doesn't? I'll be down at 1930.” He winked at her and she swatted his arm with a laugh and shooed him up the stairs.

At 1930 on the dot, John raised his hand to knock on Mrs. Hudson's door, but she opened before he could. John whistled low. “Missus Hudson. You look stunning” 

She wore a black long sleeved dress with a high neck and a train just long enough to sweep the floor. The bodice was fitted, and the fabric did a complicated, yet flattering twist just at her waist. John only noticed the slits in the side seams of the skirt when she did a little turn a flash of red silk caught the light. He squeezed his eyes shut in attempt to delete the image, and instead complimented her choice of simple, elegant pearls and the way she had her hair swept back.

“And don't you look dashing, Doctor?” She twisted her finger in the air indicating John should turn around as well.

John did look dashing. He knew it, and it was none of his own doing. The black bespoke suit, the crisp white shirt, and the deep indigo tie had all been hand selected by Sherlock for a case. John had only ever worn the whole thing once.

“Shall we?” John held out his arm for Mrs. Hudson, and he let her lead them out to the street and around the corner to where she'd parked quite literally the most magnificent piece of automotive art John had ever seen. She fished the fob from her clutch and dropped it into John's hand.

“Drive carefully… Just, not too carefully. You have my permission to have a bit of fun with it, dear. But just for tonight, understand. For Sherlock.” She let John help her into the car.

“For Sherlock,” John agreed seriously, though as he made his way around the boot of the car, he could not hide his wide grin. Fun indeed. 

They arrived at the Science Museum in record time, and John bypassed the valet parking in order to keep the car accessible. They walked at an easy pace, enjoying the lovely evening air, and eventually joining the crowd of others attending the gala. The nearer they got to the entrance, the more tightly Mrs. Hudson held to John’s arm.

“Are you sure you want to?” He whispered to her. She only gave him a withering look and a quick nod in response. “There's no guarantee this will work.”

“Hush now,” she scolded. “Trust me John. I was married to the head of a drug cartel after all.”

“True,” John laughed and patted her hand on his arm. “We’re close.”

Gradually, Mrs. Hudson’s smile melted into something more somber. She withdrew a handkerchief and dabbed her brow and behind her ears daintily. 

“You all right?” John asked, his voice raised in mild alarm.

“Fine, love. Just a bit peaky is all.” Mrs. Hudson fanned herself with her handkerchief. “It's warm. Isn't it awfully warm?”

“Uhm, no, not really.” Concern etched on his face, John glanced around. “Do you need to sit? Maybe some water?”

“Don’t be-” she swooned against John's chest. They were next in line to show their tickets -- tickets that didn't actually exist -- and were being closely watched by security. “I’ll be fine.” Mrs. Hudson stumbled a bit. “‘M fine.” John wasn’t prepared for her to twitch and drop with the finesse of a bowl of petunias. He caught her with ease, though he hadn't put much thought to his bruised ribs until just then.

“Damn,” John grunted as he lowered Mrs. Hudson to the pavement. He made a show of checking her pulse and breathing as security surrounded them. Leaning in, John whispered low, “give a bloke a warning next time, yeah?” Mrs. Hudson opened her eyes enough to wink up at him, then let her eyes roll back and her head loll. “You've been around _him_ far too long.”

“ _Sir,_ ” a solid hand landed on John's shoulder. “Is there a problem?”

John glanced up into the bruised face of Suit Three. Fantastic. “Yes, obviously. She's fainted, and I need to call to have someone bring her medication. Dodgy heart. Is there an office or a room inside I can take her to?”

“The university medical center is just that way.” Suit Three smirked and motioned with his head.

“Which will be a last resort once I have her meds here. Are you going to help us, or do I have to make a scene in front of all these people?” John's voice rose steadily as he spoke, commanding the attention of everyone within earshot. The crowd began to murmur about the poor woman and the vile goon who wouldn't let that kind young man just help her.

“I believe you've already created your scene, haven't you, Doctor?” Suit Three paused as if taking orders over his earpiece, and then stepped back and motioned to the doors. “I'm to see you into the staff offices just over here.” He did not move to help.

“Of course not,” John grumbled as he stood, gathered up a mostly limp Mrs. Hudson, and struggled into the building with his shoulder and ribs screaming. “Bastard. He's the one who bruised my damn ribs,” John mumbled.

“Language, dear,” Mrs. Hudson seemed to glare at him even with her eyes closed. Suit Three glanced back at them, then held a door open for them. He lead them down a corridor of offices, and John spotted a small break room along the way. They stopped at an office that appeared unoccupied, but had a couch and some chairs in it.

Gently arranging Mrs. Hudson on the couch, John fished out his mobile and pulled up Molly’s number. “I need to call for her meds, can you watch her for a tick?” John turned his back as Suit Three glared at him but stepped next to Mrs. Hudson.

“John?” Molly sounded like nervous, excited energy condensed.

“Nitro.”

“Got it. Be there in ten.” She sounded giddy.

“Main entrance. They'll be expecting you.” John disconnected the call and turned just in time to see Suit Three lean in over Mrs. Hudson. “Hey!”

He took a step forward as Mrs. Hudson sat up abruptly and took a swing, her fist landing solidly against Suit Three’s already broken nose. She wouldn't have done much damage, but under the circumstances, he started bleeding heavily. 

“It’s what you deserve, for you and your men treating my boys the way you did. Do it again, and you'll get worse!” She had nearly worked herself into a rage.

“Mrs. H!” John chuckled. “You're supposed to be sick!” He manhandled Suit Three into a chair, handed him a handkerchief, and directed him to lean forward.

“Well, I don't like _him,_ ” she stated bluntly as she swung her legs over the edge of the couch and sat up properly.

“I don't much either,” John shook his head at her fondly, “but we need him for the plan.” John glanced out the door and back. “There's a staff lounge. I'll get you some ice, though I am not inclined to do so. Can you two play nice for just a moment?” Suit Three groaned and Mrs. Hudson nodded her head demurely.

John ducked into the hallway, pulling the door closed behind him, and headed in the opposite direction. He followed a series of dimly lit corridors and let the noise of the ongoing party guide him. He soon found himself in the hallway the caterer was using to bring the food out to the party guests.

“Brilliant,” John dug around until he found what he was looking for. A rack of telltale server uniforms. Maroon waistcoats, white gloves, and black bowties. Easy. He changed from his suit coat and tie -- Sherlock wasn't going to be happy -- to one of the mundane uniforms (making certain it was loose enough to conceal his gun), pulled on a pair of gloves, and grabbed a tray of hors d'oeuvres from a warmer.

A quick glance and John spotted Sherlock looking miserable and bored, a potentially dangerous combination in any setting. He was wearing a fresh suit, and no evidence of their earlier encounter with the brute squad could be seen. He stood near a refreshment table, an untouched flute of champagne held lazily in his left hand. Spouting off angry deductions at anyone who dared approach him, Sherlock wore his most intense, vitriolic glare. Suit One and Suit Two were stationed nearby. 

Sherlock was in the middle of deducing a stately gentleman into shocked outrage when he was distracted by Suit One motioning to Suit Two. They both took off running back the way John had come from. John had managed to stay mostly concealed behind a pillar, and stepped up next to Sherlock just as he picked an hors d'oeuvre up off the table. He examined it closely. Sniffed it. Licked it once. Twice. Took a tiny bite, frowned, and placed the food back on the tray.

“If I may, sir. You might find these… something wrapped in some sort of cheese then wrapped in something else things more to your liking.” John tried to sound professional. Sherlock rolled his eyes.

“Serve staff. Original.” He did take an offering from John's tray and hummed in approval as he took another. “Took you long enough.”

“I'm here, aren't I?” John put the tray on the table and started removing his gloves. “You ready?”

“Won't my security detail be suspicious?”

“Nah. I have a feeling they're responding to the fact that I got away from my guy.” He couldn't help but chuckle. “I left him with a bit of a distraction.”

“Do tell,” Sherlock motioned for John to lead the way, and they skirted a wide berth around most of the party goers.

“Mrs. Hudson, she's a marvel.”

“Hmm. Indeed. You never let me include her on cases before,” Sherlock pouted. “I tried to tell you she's more than capable.”

“She is.” John turned down a corridor with an illuminated exit sign at the end, and quickened his pace. “But there was no chance of injury or death for this plan. Well, at least not for her.” He glanced up at Sherlock. “She punched a guy. Bloody mess it was. Hit him right in his already broken nose. It was fantastic.”

Sherlock gave John a discerning once over, his eyes pausing at the bruise on John's jaw. “Broken nose. It was the man who assailed you earlier. Facial contusions. Your shoulder is aching. _Bruised ribs._ ” He growled the last bit. 

“It's fine, yeah? Let's just get out of here. Molly's got Mrs. H. by now.” John stepped aside and dropped the gloves and bowtie in a bin as Sherlock crouched to disengage the mechanism that would trigger the fire alarm. “You owe me dim sum.”

“It's not _fine._ Bruised ribs falls clearly into the excessive force category.” Brushing his hands off, Sherlock stood and pushed the door open.

“To be fair, I did break his nose.” John scanned their surroundings and stepped cautiously through the door. The car was only a block away.

“He surprised you. He had to expect you to put up a fight.” They made their way stealthily along the side of the Museum, trying to stay in the shadows.

“Guys like him, like me, once we get into that fight or flight mode, it's hard to turn it off.” Motioning for Sherlock to get behind him, John carefully reached for his gun.

“You aren't like him,” Sherlock whispered near John's ear. “You have a strong moral code, where he sold his soul to work for my lazy, fat, moronic brot-”

“William!” A figure dressed in red and sequins, with a cigarette held loosely between her fingers, stepped out from a shadow. “Don't you talk about your brother that way.”

“Mummy!” Sherlock looked, for once, truly stunned. “What are you… Why? Are you _smoking_?” Mouth agape, he stared at her as if she'd grown a second head.

“Close your mouth, love. It'll freeze like that,” she patted his cheek fondly. “This I just lifted from your brother. He thinks I don't know he still smokes, but I'm his mother, of course I know that my sons, both of them, still smoke. It's just for the nerves, mind. You know I hate these things,” she waved her hand towards the gala, carrying on without them, “but between your father's constant nagging, and your brother's incessant need to interfere…”

“Yes, mummy,” Sherlock mumbled, looking every bit the contrite son.

“And you,” Mummy turned her attention to John, “must be Doctor Watson. I've heard so much about you. Well, not from this one, I'm sure you know how he is. But Mycroft is always fussing about the trouble you two get into. Oh, and your blog. I never miss it.” Finally pausing to take a puff of her cigarette, Mummy stuck her hand out to John.

“Mummy?” Confusion etched on his face, John glanced between Sherlock and this sequin-clad, high energy, though ordinary looking enough, woman, and then back to Sherlock. “This is your mum?”

“Yes, and I'd thank you to not point your gun at her,” Sherlock snapped and crossed his arms over his chest with a huff.

“Oh… Damn, sorry.” John fumbled the gun he hadn't realized he'd pulled out, and concealed it at his back. “It's lovely to meet you, Mrs. Holmes. So, so sorry about the…”

“Don't you worry about a thing, dear.” Shaking his hand, Mummy pulled John into an embrace. “You were protecting my William, as I know you always do. And I'm glad for it.” She held John at arm’s length and looked him up and down, then turned to Sherlock. “He's lovely dear. I'm so glad you finally found-”

“Dim sum,” John blurted out awkwardly, in attempt to derail Mummy’s line of thought. He was glad to see Sherlock looked at least marginally as uncomfortable as he felt.

“I'm sorry dear?”

“Dim sum. We were going to get dim sum.”

“Oh, sounds lovely. Care if I join you?” Mummy stubbed out her cigarette, then wrapped one hand around Sherlock’s arm, and the other around John's.

“You… You can't leave. This party is for you!” Sherlock finally spoke. “What about father?”

“I already said I hate these things. They're celebrating the anniversary of a book I haven't looked at since I published it! And your father doesn't know a stranger, he'll never know I'm gone.”

“Excuse me. What do the three of you think you are doing out here?” Looking more thunderous than usual, Mycroft stormed around the corner of the building and stomped right up to them.

“Well, I was getting some fresh air,” Mummy supplied.

“John came to sneak me away.” Sherlock pulled his arm away from Mummy and crossed his arms over chest. 

“And I think we're about to have dim sum. I certainly hope so, I'm famished,” John supplied helpfully.

“No,” Mycroft snapped. “I went to great lengths to make this evening perfect.” He turned to Mummy. “I even managed to get Sherlock here for you. It wasn't easy…”

“When is it ever?” John mumbled and Mummy giggled.

“But I devised a foolproof plan to get him here, to get Doctor Watson here as well.” With a smug smirk Mycroft turned to John. “There was no need for all the sneaking, your name was already on the list. Your antics, acting as if you were facing off against one of the villains in your romanticized tales, this evening proved you are nothing more than a fool…”

“How dare you!” Sherlock shoved Mycroft back. “Your men attacked us on the street. I was drugged, John was injured, and he devised a plan to extract me from an environment we both felt was hostile.” He spat the last words at his brother.

“Myc! Did you order your men to do those things?” Mummy’s eyes flashed, and the effect was terrifying. Mycroft slid a finger under his collar and cleared his throat. “Answer me young man!”

“They weren't expecting Doctor Watson to fight back,” he offered lamely.

“The hell?” John growled. 

“I am very disappointed,” with a tsk, she turned and faced John. “Are you all right dear?” Wide eyed, John nodded slowly. She patted his arm. “Good. And you love?”

Sherlock nodded and let his mother embrace him. He sneered at Mycroft over her head. “Yes, mummy.”

“The foolish one here is you, Mycroft.” John stood at parade rest and glared. “I had already convinced Sherlock that tonight was non-negotiable. We were already coming. Even sent in our RSVP, have your assistant check. You've wasted all this time and these resources, and had you not assumed the worst of your brother, all of this could have been avoided.”

“I… Uhm…” Mycroft would not meet John's eye.

“Mycroft, you march yourself back inside, and you manage this party. And watch how many sweets your father eats. I'll be back soon.” Taking each of them by the arm again, Mummy started leading John and Sherlock away. “March, young man!”

“Yes, mummy,” Mycroft mumbled. He kicked at a rock and slowly made his way back to the gala.

“Now, how are we making our getaway?” Mummy looked to John.

Holding up the keys, John grinned. “I've got Mrs. Hudson's Aston Martin.”

“I'm driving!” Sherlock tried to snatch the keys, but John was too quick.

“No, love. My nerves can't handle that, and Mrs. Hudson trusted the car to John.”

“But, mummy!” Sherlock whined.

“No buts, William.”

“Fine, but I get to sit up front.” Diving for the door, John stopped him.

“You are not making your mother climb into that back seat.” John eyed the cramped space, and then gave Sherlock a teasingly appraising look. “Yeah, I'm sure it'll be fine.”

“Maybe I'll just stay here then!” With a petulant stomp of his foot Sherlock pouted.

John shrugged and opened the door for Mummy. “Suit yourself.”

“Enjoy dear. John will bring you something back.” Blowing him a kiss, Mummy took a step towards the car.

“Dim sum was _my_ idea.” With a huff, Sherlock pushed past them and wedged himself into the back of the car. John and Mummy shared a knowing look, and he helped her into her seat.

“Everyone settled?” John buckled his seatbelt.

“Ready,” Mummy smiled.

“Famished,” Sherlock grumbled, causing John to chuckle.

“Okay. Hold tight.”

**Author's Note:**

> My apologies for the delay with this story. I've been ill, was actually in hospital for three days, but I'm getting better and trying to get caught up. ♡


End file.
